1.select默認是inline元素，你可以
select
{
display:block;
}
2.默認select會選擇第一項option，如果初始狀態不選可以：
jq寫法：
$("select").each(function(){this.selectedIndex=-1});
或者干脆加個冗余option：
<select>
<option>請選擇網站...</option>
<option value="http://www.qq.com">騰訊網</option>
<option value="http://www.163.com">網易</option>
<option value="http://www.google.com">谷歌</option>
</select>
注：
The selectedIndex property returns -1 if a select object does not contain any selected items. Setting the selectedIndex property clears any existing selected items.
The selectedIndex property is most useful when used with select objects that support selecting only one item at a time—that is, those in which the MULTIPLE attribute is not specified.
3.獲取選擇項的值：
<select id="ddlCities" onchange="alert(this.options[this.selectedIndex].value);">
<option value="0">北京</option>
<option value="1">濟南</option>
<option value="2">威海</option>
</select>
獲取文本：
this.options[this.selectedIndex].text
更簡潔的直接selectObj.value
4.多選
<select id="ddlCities" multiple="multiple" size="2">
<option value="0">北京</option>
<option value="1">濟南</option>
<option value="2">威海</option>
</select>
使用jq獲取選擇，僅測試所以寫在標簽上：
<select id="ddlCities" multiple="multiple" size="2" onchange="alert($(this).find('option:selected').text());">
<option value="0">北京</option>
<option value="1">濟南</option>
<option value="2">威海</option>
</select>
如果純js寫，需要循環了：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>無標題文檔</title>
<style type="text/css">
select
{
display:block;
}
</style>
<script type="text/javascript">
function ddlCities_onchange(theSel)
{
var arr=[];
for(var i=0;i<theSel.options.length;i++)
{
if(theSel.options[i].selected)
arr.push(theSel.options[i].innerText);
}
alert(arr.join());
}
</script>
</head>
<body>
<select>
<option>請選擇網站...</option>
<option value="http://www.qq.com">騰訊網</option>
<option value="http://www.163.com">網易</option>
<option value="http://www.google.com">谷歌</option>
</select>
<select id="ddlCities" multiple="multiple" size="2" onchange="ddlCities_onchange(this);">
<option value="0">北京</option>
<option value="1">濟南</option>
<option value="2">威海</option>
</select>
</body>
</html>
5.添加移除option:
jq添加：
$("<option value='3'>南京</option>").appendTo($("#ddlCities"));
js寫法：
var anOption = document.createElement("option");
anOption.text="南京";
anOption.value="4";
document.getElementById("ddlCities").options.add(anOption);
或者 document.getElementById("ddlCities").add(anOption);
